Collaborative Research: Can Human-Induced Turbidity Currents Enable Sustainability of Freshwater Reservoirs?

合作研究：人为引起的浊流能否实现淡水水库的可持续性？

• 批准号: 2317835
• 负责人: Keith Gido
• 金额: $ 15万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317835&HistoricalAwards=false
• 关键词: Collaborative; Research; Human; Induced; Turbidity

Water reservoirs provide many societal services in the United States and worldwide including flood control and sources of hydroelectric power, drinking water, and irrigation for agriculture and farming. Despite their vital roles, reservoirs are gradually being filled with sediments as land use and climate change exacerbate soil erosion and sediment transport and deposition in natural and engineered surface water systems. Few suitable sites for new dam construction exist in the United States thereby emphasizing the need for cost-effective management of existing reservoirs. In 2024, the US Army Corps of Engineers (USACE) and the State of Kansas are scheduled pilot a novel water-injection dredging (WID) process (an untested but potentially transformative approach) in a federal reservoir in the State of Kansas with the aim of inducing turbidity currents and exporting trapped reservoir sediments to downstream waterways, which could prove crucial for addressing the global concern of reservoir sedimentation and its impact on water security. However, key questions remain regarding the ability of WID to restore reservoir sediment storage capacity, its environmental implications to in-lake water quality, and its downstream effects to channel morphology and aquatic ecosystems. To address these knowledge gaps, the Principal Investigators (PIs) of this project propose to leverage the USACE-Kansas WID field test to collect and analyze sediments, nutrients, and aquatic species count data with the goal of generating fundamental scientific and engineering knowledge on the transport efficacy, mechanisms, and environmental responses following the implementation of WID process in a water reservoir. If WID is shown to be viable, with minimal impact on downstream river ecosystems, the successful completion of this project will benefit society through the generation of new data and fundamental knowledge that could be used in reservoirs around the globe, transforming sediment management, and reducing costs associated with existing dredging techniques. Additional benefits to society will be achieved through student education and training including the mentoring of one undergraduate and one graduate student at the University of Kansas and two undergraduate students and one graduate student at Kansas State University.Existing reservoir sediment management techniques have limited effectiveness because they (1) do not restore natural downstream sediment continuity, (2) require transport, storage, and disposal of dredged materials, and (3) are costly to implement. The basic premise of the water-injection dredging (WID) process is to spray a jet of fluid into the bed of a reservoir, entrain sediments into the overlying water, and initiate a density current (akin to an underwater avalanche) to mobilize stored bed sediments toward the reservoir outlet. While WID has successfully been applied to ports and rivers, it has yet to be tested in a water reservoir thereby raising critical questions regarding its potential efficacy and environmental impact. This project will address these knowledge gaps. The specific objectives of the research are to 1) evaluate the physical mechanisms by which human-induced turbidity currents propagate in reservoirs, using high-frequency turbidity sensing data and computational fluid dynamics modeling; 2) evaluate shifts in reservoir water quality by monitoring thermal stratification and redox conditions using in-situ physicochemical sensors and laboratory experiments before, during, and after the WID field test; 3) assess channel and floodplain accretion rates before, during, and after the WID field test; and 4) continuously assess the response of fish and macroinvertebrate communities to sediment releases and the induced biological, chemical, and physical changes in water quality and habitats throughout the WID demonstration project. The successful completion of this research could transform how reservoirs are managed, potentially extending the usable lifetime of large water storage infrastructure across the globe. To implement the educational and training goals of this project, the Principal Investigators (PIs) will collaborate with the University of Kansas (KU) Self Engineering Leadership Fellows (SELF) program to develop and deliver a workshop for college students to conduct hands-on research with large environmental datasets and develop science communication skills, culminating in a presentation to the State of Kansas and Army Corps of Engineers. In addition, the PIs plan to integrate the findings from this research into relevant course modules and outreach activities at KU and Kansas State University.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

水库在美国和世界各地提供许多社会服务，包括防洪以及为农业和农业提供水电、饮用水和灌溉的来源。尽管水库发挥着重要作用，但由于土地利用和气候变化加剧了土壤侵蚀以及天然和工程地表水系统中的泥沙输送和沉积，水库正逐渐被泥沙填满。美国几乎没有适合修建新大坝的地点，因此强调了对现有水库进行具有成本效益的管理的必要性。2024年，美国陆军工程兵团(USACE)和堪萨斯州计划在堪萨斯州的一个联邦水库试行一种新的注水疏浚(WID)工艺(这是一种未经测试但具有潜在变革意义的方法)，目的是诱导浑浊水流，并将滞留的水库沉积物输出到下游水道，这可能被证明对解决全球对水库沉积及其对水安全的影响至关重要。然而，WID恢复水库沉积物储存能力的能力、其对湖内水质的环境影响、以及其对河道形态和水生生态系统的下游影响，仍然是关键问题。为了弥补这些知识空白，该项目的首席调查员建议利用USACE-堪萨斯WID现场测试来收集和分析沉积物、营养物质和水生物种计数数据，目的是在水库中实施WID过程后产生关于运输效率、机制和环境反应的基本科学和工程知识。如果WID被证明是可行的，对下游河流生态系统的影响最小，该项目的成功完成将通过产生可用于全球水库的新数据和基础知识，改变沉积物管理，并降低与现有疏浚技术相关的成本，从而造福社会。还将通过学生教育和培训为社会带来更多好处，包括对堪萨斯大学的一名本科生和一名研究生以及堪萨斯州立大学的两名本科生和一名研究生进行指导。现有的水库泥沙管理技术的有效性有限，因为它们(1)无法恢复下游泥沙的自然连续性，(2)需要运输、储存和处置疏浚材料，以及(3)实施成本高昂。注水疏浚(WID)过程的基本前提是将一股流体喷射到水库的河床中，将沉积物卷进上覆水中，并引发密度流(类似于水下雪崩)，将储存的河床沉积物动员到水库出水口。虽然WID已经成功地应用于港口和河流，但它还没有在蓄水池中进行测试，因此提出了关于其潜在效力和环境影响的关键问题。该项目将解决这些知识差距。这项研究的具体目标是：1)利用高频浑浊传感数据和计算流体动力学模型，评估人类诱导的浑浊流在水库中传播的物理机制；2)通过使用原位物理化学传感器和实验室实验，在WID现场试验之前、期间和之后监测水库水质的热分层和氧化还原情况；3)评估WID现场试验之前、期间和之后的河道和滩涂沉积速率；4)在整个WID示范项目中，持续评估鱼类和大型无脊椎动物群落对沉积物释放的反应以及引起的水质和栖息地的生物、化学和物理变化。这项研究的成功完成可能会改变水库的管理方式，潜在地延长全球大型储水基础设施的可用寿命。为了实现该项目的教育和培训目标，首席调查员(PI)将与堪萨斯大学(KU)自我工程领导力研究员(SELF)计划合作，为大学生开发和提供一个研讨会，以进行大型环境数据集的实践研究，并发展科学交流技能，最终向堪萨斯州和陆军工程兵部队进行演示。此外，PIS计划将这项研究的结果整合到KU和堪萨斯州立大学的相关课程模块和外展活动中。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。